1. Field of the Invention
The present invention relates to a mobile phone terminal which controls the execution of multiple programs, to a program management method and to a computer program which performs it.
Priority is claimed on Japanese Patent Application No. 2004-315697, filed Oct. 29, 2004, the content of which is incorporated herein by reference.
2. Description of Related Art
With prior art technique, in a single task operating system, in order to perform multi task like operation in which multiple programs are processed at the same time, thread history for application programs which are operating is stored in the memory of an OS (Operating System). Whether or not there is an application program which is requesting operation for the next is monitored by the operating system with a timer or the like. If there is an application program which is requesting operation for the next, that application program is added to the application program thread history, and the operating system shifts its operation to that application program. When shifting in order again to operate the application program which was executing before, a system has been practiced in which the processes are shifted one at a time by reading in order from those which have been stored first in the stored thread history (for example refer to Japanese Unexamined Patent Application, First Publication No. H06-44084).
The technique described in Japanese Unexamined Patent Application, First Publication No. H06-44084 is an example of operation upon a personal computer, upon which more processing capability is available than a mobile phone terminal, and moreover in which the ratio of occasion of unexpected interruptions of operation, for example due to incoming calls, is low.
With a prior art technique for a mobile phone terminal, even though activation requests for multiple application programs are issued by the timer or the like, it has not been possible to start processing the next application program without finishing the processes one at a time. Furthermore, it has also not been possible to maintain multiple states of application programs which were executed before in storage. Due to this, with the mobile phone shown in the prior art technique of references #2 (Japanese Unexamined Patent Application, First Publication No. 2003-319020), operation has been performed by individual monitoring when an event such as incoming calls or the like occurs, referring to the type or the state of the application program.
With a mobile phone terminal, for application programs which are implemented by the maker of the mobile phone, operation is performed so as to operate in a multi-tasking manner with a small memory capacity, by implementing a different technique from those disclosed in Patent References #1 and #2, in order to comply with a small memory capacity.
Now, with recent mobile phone terminals, apart from the application programs which are implemented as a standard (or originally installed) by the mobile phone terminal maker, there are programs such as games and the like which the user downloads and uses by operating the mobile phone terminal via a network (hereinafter termed “downloaded programs”). Such downloaded programs are almost always built according to a common specification, in order to act on any mobile phone terminal operating system from any maker.
However, these downloaded programs are not designed based upon the assumption that they process according to the multi-tasking operation which is implemented by the individual mobile phone maker. Due to this, if a downloaded program and a program which is implemented as a standard are activated together upon the operating system, when shifting between these programs, there is the problem that the program which is implemented as a standard undesirably performs restart operation which is not anticipated by the user.